Please use either the Harvard or the IEEE style of referencing.  You can find a guide to both these styles on the library pages:
 http://www.librarydevelopment.group.shef.ac.uk/referencing.html (ignore the departmental information, look for a guide for one of these references styles).

If you have any questions about referencing, or are unsure about how to reference your work, please discuss this with your project supervisor. It is extremely important to ensure your work is referenced correctly.